Constrained networks include, for example, Low power and Lossy Networks (LLNs), such as sensor networks. These constrained networks have a myriad of applications, such as Smart Grid, Smart Cities, home and building automation, etc. Various challenges are presented with LLNs, such as lossy links, low bandwidth, battery operation, low memory and/or processing capability, etc. Large-scale internet protocol (IP) smart object networks pose a number of technical challenges. For instance, the degree of density of such networks (such as Smart Grid networks with a large number of sensors and actuators, smart cities, or advanced metering infrastructure (AMI) networks) may be extremely high. For example, it is not rare for each node to see several hundreds of neighbors. This architecture is particularly problematic for LLNs, where constrained links can wreak havoc on data transmission.
Network deployments utilize a number of different link technologies, including RF, Powerline Communications (PLC), and cellular. Each link technology provides its own set of strengths and weaknesses. LLNs communicate over a physical medium that is strongly affected by environmental conditions that change over time. Some examples include temporal changes in interference (for example, other wireless networks or electrical appliances), physical obstruction (for example, doors opening/closing or seasonal changes in foliage density of trees), and propagation characteristics of the physical media (for example, temperature or humidity changes). PLC link technologies, for example, are known to experience significant unpredictable noise that depends on the quality of the electric lines and the kinds of electric devices attached to the network.